According to the U.S. Department of Energy, hot water heating costs the average homeowner between 15% and 30% of a home's energy use.
Modern solar water heaters are flush mounted, attractive units that can cut energy bills while providing ample hot water for your home, heating needs, and even swimming pool. PATH looks at two kinds of solar water heaters: passive and forced circulation.Both systems have collectors and storage tanks to hold the heated water. The collectors are flush-mounted units installed on top of the roof and look very much like a skylight. They contain a flat copper plate painted black with water tubes attached to absorb the solar energy. As the sun shines on the copper plate, the heat is absorbed and transferred to the water flowing through the tubes.
For passive systems, the heated water in the tubes moves to the storage tank by natural convection; in a forced-circulation system, the water is moved with a pump. In warmer climates, the forced circulation'style system can provide 80 to 100 gallons of hot water to the home per day and costs about $3,000 to install. Passive systems provide less water but can be installed for as little as $1,000.
More about solar hot water heaters: